Hello, I have excessive engine oil consumption, about 1.5 litres over 2500 km, there is no oil leakage or smoke from the exhaust, nor is there any oil in the antifreeze fluid.

The car has 187000 km, starts and runs great on both gas and petrol, engine light off parameters ok. Serviced regularly and normal use not short stretches. I also cleaned the oil vapour ducts in case they caused me abnormal pressures.
Can you explain why and give me a solution to the problem?

Thank you very much